(a) Field of the Invention
The present invention relates to a microphone, a method of manufacturing a microphone, and a method of controlling the microphone. More particularly to a method of manufacturing a microphone which selectively implements directional characteristics of a microphone, based on noisy environments, a microphone, and a method of controlling the microphone.
(b) Description of the Related Art
In general, a microphone is a device configured to convert sound into an electrical signal. The microphone may be used for mobile communication devices including a terminal, and various communication devices including an earphone or a hearing aid. The microphone requires high audio performance, reliability, and operability. A capacitive microphone based on Micro Electro Mechanical System (MEMS) has high audio performance, reliability, and operability, as compared with an electret condenser microphone (ECM microphone).
The MEMS microphone is classified into a non-directional (omnidirectional) microphone and a directional microphone, based on the directional characteristics. The non-directional microphone has substantially uniform sensitivity for incident sound waves in all directions. Conversly, the directional microphone has different sensitivity based on the directions of incident sound waves, and is classified into a unidirectional type and a bidirectional type in accordance with the directional characteristics. For example, the directional microphone is used for recording in a narrow room or capturing only desired sounds in a room with numerousreverberations.
When the microphones are mounted within a vehicle, sound sources are distance therefrom and noise is variably generated due to the environmental characteristics of the vehicle, and thus there is a need for a microphone that is functional in the noisy environment in the interior of the vehicle. The directional MEMS microphone captures sounds only in the desired directions. However, since the directional microphone of the related art captures sounds only in desired directions, it is functional against surrounding noise, but the sensitivity is low and the frequency response characteristic are poor compared with the non-directional microphone.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.